A wire is joined to points X and Y in the circuit diagram shown.

Question

A diagram of a circuit with a power source on the left. Directly above the power source is a dot labeled X and then a circle with an X in it. The circuit then splits with one path straight back to the power source and the other path has 3 circles with X in them labeled 2, 3, and 4 respectively. There is a point labeled Y between circles 2 and 3.A diagram of a circuit with a power source on the left. Directly above the power source is a dot labeled X and then a circle with an X in it. After the x are 4 different circles on the circuit with Xs in them labeled 1, 2, 3, and 4 respectively. There is a point labeled Y in between circles 2 and 3. There is a branch of the circuit from X to Y.

How does the circuit change when the wire is added?

A closed circuit occurs and makes all bulbs turn off.
An open circuit occurs and makes all bulbs turn off.
A short circuit occurs and makes bulbs 3 and 4 turn off but keeps bulbs 1 and 2 lit.
A short circuit occurs and makes bulbs 1 and 2 turn off but keeps bulbs 3 and 4 lit.

Answer 1

To understand how the circuit changes when a wire is added between points X and Y, let's analyze the circuit based on the given description.

1. You have a power source on the left, and it initially splits into two paths.
2. The circuit has several bulbs (labeled with X's and numbers).
3. Point Y is located between bulbs 2 and 3.

When a wire is added directly between points X and Y, it creates a new path for the current to flow. Since wires typically provide very low resistance, most of the current will flow through the wire rather than through the bulbs in the circuit.

Based on this configuration:

• The wire from X to Y essentially bypasses the path that includes bulbs 1 and 2, creating a short circuit condition for that part of the circuit.
• Hence, bulbs 3 and 4 will continue to receive current and remain lit, while bulbs 1 and 2 will not receive sufficient current and will turn off.

Therefore, when the wire is added, the correct answer is:

A short circuit occurs and makes bulbs 1 and 2 turn off but keeps bulbs 3 and 4 lit.